This invention relates to grinding machines, and more particularly to an improved, unique type of grinding machine for grinding the cutters in saw chain cutter links.
Conventional saw chain, as such has developed in the United States and throughout the world, includes a series of cutter links provided at spacings along the length of the saw chain and interconnected to each other by other links such as tie strap links and center links. A cutter link typically includes a depth gauge at the forward end of the link integral with and projecting upwardly from the body portion of the link, and a cutter also joined to the body portion of the link and projecting upwardly from this body portion at the rear of the cutter link. The depth gauge and cutter are separated by a gullet. The cutter links include so-called left-hand cutter links, where the cutter link is a side link located on the left side of the chain (viewing the chain in the direction in which it travels during cutting), and right-hand cutting links where the cutter link is a side link appearing on the right side of the chain. It is usual in a cutting chain to intersperse left-hand cutter links with right-hand cutter links, so that successive links in a chain are of opposite hand.
A grinding wheel properly positioned to grind the cutting edge of a cutter in a left-hand cutter link has a general plane which is inclined relative to the cutter link, and this incline is opposite to the incline of the plane of a grinding wheel properly positioned to grind the cutting edge in the cutter of a right-hand cutter link. As a consequence, it is common in cutter grinding machines to set the grinding machine up so that the support for the saw chain and the grinding wheel are properly relatively positioned for the grinding of cutter links of one hand. The machine is then operated to grind all the cutter links of this hand in the saw chain. The machine is then set up for grinding cutter links of opposite hand, and the chain then rerun through the machine to grind links of opposite hand. This requires that the chain, in effect, be run in two complete passes through the grinding station of the machine. A machine of this description is illustrated in my earlier U.S. Pat. No. 4,044,635.
A machine of the above description does not lend itself to a completely automatic type of operation. Further, care must be taken that cutters in links of one hand sharpened during one pass of the chain through the machine are not inadvertently dulled with passage of the chain in another pass through the machine for the purpose of grinding cutters in links of opposite hand. Furthermore, the necessity for making adjustments in the machine before all the cutters are capable of being sharpened tends to increase the time that it takes to sharpen all the cutter links in the chain.
A general object of this invention, therefore, is to provide an improved grinding machine for grinding the cutters of cutter links in saw chain which is capable of grinding all the cutters without making an intermediate adjustment in the machine.
Another general object is to provide a grinding machine which may function to grind cutter links of alternating hand as they successively appear in a saw chain, with one pass of the saw chain through the machine.
Another object is to provide a cutter grinder of the above general description which includes a pair of power-rotated grinding wheels as part of a pair of grinding wheel assemblies. Provision is made whereby one grinding wheel may be shifted bodily to move its edge into a cutter link occupying a grinding station in the machine, this wheel being properly positioned to produce grinding of cutters in links of one hand. The grinding wheel of the other assembly is positionable to move its edge into a cutter link occupying the grinding station, with this wheel being properly positioned to produce grinding of cutters in links of opposite hand.
Yet another object of the invention is to provide a grinding machine with a pair of power-rotated grinding wheels as above described, which further includes means operatively interconnecting the grinding wheel assemblies coordinating their movements automatically, whereby when grinding the cutters of a saw chain, and with automatic positioning of successive cutter links in a cutting station, first one and then the other grinding wheel will be shifted to produce proper grinding of the cutter in the particular cutter link occupying the grinding station.
Another object of the invention is to provide a grinding machine which is substantially fully automatic in operation, and which is operable to grind the cutters of all the cutter links in a saw chain with one pass of the saw chain through the machine.